1
|
Han B, Zhang L, Geng L, Jia H, Wang J, Ke L, Li A, Gao J, Wu T, Lu Y, Liu F, Song H, Wei X, Ma S, Zhan H, Wu Y, Liu Y, Wang Q, Diao Q, Zhang J, Dai P. Greater wax moth control in apiaries can be improved by combining Bacillus thuringiensis and entrapments. Nat Commun 2023; 14:7073. [PMID: 37925529 PMCID: PMC10625538 DOI: 10.1038/s41467-023-42946-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 10/26/2023] [Indexed: 11/06/2023] Open
Abstract
The greater wax moth (GWM), Galleria mellonella (Lepidoptera: Pyralidae), is a major bee pest that causes significant damage to beehives and results in economic losses. Bacillus thuringiensis (Bt) appears as a potential sustainable solution to control this pest. Here, we develop a novel Bt strain (designated BiotGm) that exhibits insecticidal activity against GWM larvae with a LC50 value lower than 2 μg/g, and low toxicity levels to honey bee with a LC50 = 20598.78 μg/mL for larvae and no observed adverse effect concentration = 100 μg/mL for adults. We design an entrapment method consisting of a lure for GWM larvae, BiotGm, and a trapping device that prevents bees from contacting the lure. We find that this method reduces the population of GWM larvae in both laboratory and field trials. Overall, these results provide a promising direction for the application of Bt-based biological control of GWM in beehives, although further optimization remain necessary.
Collapse
Affiliation(s)
- Bo Han
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Li Zhang
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Huiru Jia
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jian Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Li Ke
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Airui Li
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jing Gao
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Tong Wu
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Ying Lu
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Feng Liu
- Jiangxi Institute of Apicultural Research, Nanchang, 330201, China
| | - Huailei Song
- Shanxi Agricultural University, Taiyuan, 030006, China
| | - Xiaoping Wei
- Modern Agricultural Development Institute, Guizhou Academy of Agricultural Sciences, Guiyang, 550006, China
| | - Shilong Ma
- Enshi Academy of Agricultural Sciences, Enshi, 445002, China
| | - Hongping Zhan
- Modern Agricultural Development Institute, Guizhou Academy of Agricultural Sciences, Guiyang, 550006, China
| | - Yanyan Wu
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yongjun Liu
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Qiang Wang
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Qingyun Diao
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Pingli Dai
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| |
Collapse
|
2
|
Soe ET, Naing ZL, Zhang C, Niu LL, Tang J, Yu S, Ding Z, Liang G. Cry51Aa Proteins Are Active against Apolygus lucorum and Show a Mechanism Similar to Pore Formation Model. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:2279-2289. [PMID: 36710440 DOI: 10.1021/acs.jafc.2c07244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Reduced insecticide spray in crop fields due to the widespread adoption of Bacillus thuringiensis (Bt) crops has favored the population increases of mirid bugs. Cry51Aa proteins are new types of Bt proteins that belong to aerolysin-like β pore-forming proteins with insecticidal activity against hemipteran and coleopteran pests. Here, we studied the activity of Bt Cry51Aa1 and Cry51Aa2 against Apolygus lucorum, an emerging pest in cotton, and their mechanism of action. Cry51Aa1 exhibited almost 5-fold higher toxicity than Cry51Aa2 with LC50 of 11.87 and 61.34 μg/mL, respectively. Protoxins could be activated both in vitro, by trypsin and midgut contents, and in vivo, by A. lucorum midgut. Both Cry51Aa protoxins were processed in two steps, producing pre-activated (∼30 kDa) and final activated (∼25-28 kDa) proteins. Cry51Aa proteins bound to a 25 kDa midgut protein, and Cry51Aa2 showed 2 times higher binding affinity than Cry51Aa1. Incubating Cry51Aa proteins with midgut homogenate resulted in toxin oligomers of 150-200 kDa. Our findings provide a theoretical basis for using Cry51Aa proteins to control A. lucorum and a better understanding of their mode of action.
Collapse
Affiliation(s)
- Ei Thinzar Soe
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| | - Zaw Lin Naing
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| | - Caihong Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| | - Lin Lin Niu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| | - Jinrong Tang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| | - Siqi Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| | - Zhongwei Ding
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| | - Gemei Liang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing 100193, People Republic of China
| |
Collapse
|
3
|
Harirchi S, Sar T, Ramezani M, Aliyu H, Etemadifar Z, Nojoumi SA, Yazdian F, Awasthi MK, Taherzadeh MJ. Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives. Microorganisms 2022; 10:microorganisms10122355. [PMID: 36557608 PMCID: PMC9781867 DOI: 10.3390/microorganisms10122355] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 12/02/2022] Open
Abstract
For a long time, the genus Bacillus has been known and considered among the most applicable genera in several fields. Recent taxonomical developments resulted in the identification of more species in Bacillus-related genera, particularly in the order Bacillales (earlier heterotypic synonym: Caryophanales), with potential application for biotechnological and industrial purposes such as biofuels, bioactive agents, biopolymers, and enzymes. Therefore, a thorough understanding of the taxonomy, growth requirements and physiology, genomics, and metabolic pathways in the highly diverse bacterial order, Bacillales, will facilitate a more robust designing and sustainable production of strain lines relevant to a circular economy. This paper is focused principally on less-known genera and their potential in the order Bacillales for promising applications in the industry and addresses the taxonomical complexities of this order. Moreover, it emphasizes the biotechnological usage of some engineered strains of the order Bacillales. The elucidation of novel taxa, their metabolic pathways, and growth conditions would make it possible to drive industrial processes toward an upgraded functionality based on the microbial nature.
Collapse
Affiliation(s)
- Sharareh Harirchi
- Swedish Centre for Resource Recovery, University of Borås, 50190 Borås, Sweden
| | - Taner Sar
- Swedish Centre for Resource Recovery, University of Borås, 50190 Borås, Sweden
| | - Mohaddaseh Ramezani
- Microorganisms Bank, Iranian Biological Resource Centre (IBRC), Academic Center for Education, Culture and Research (ACECR), Tehran, Iran
| | - Habibu Aliyu
- Institute of Process Engineering in Life Science II: Technical Biology, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Zahra Etemadifar
- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan 8174673441, Iran
| | - Seyed Ali Nojoumi
- Microbiology Research Center, Pasteur Institute of Iran, Tehran 1316943551, Iran
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran 1316943551, Iran
| | - Fatemeh Yazdian
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 1439957131, Iran
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, Northwest A&F University, Taicheng Road 3#, Yangling, Xianyang 712100, China
| | - Mohammad J. Taherzadeh
- Swedish Centre for Resource Recovery, University of Borås, 50190 Borås, Sweden
- Correspondence:
| |
Collapse
|
4
|
Prasanna BM, Bruce A, Beyene Y, Makumbi D, Gowda M, Asim M, Martinelli S, Head GP, Parimi S. Host plant resistance for fall armyworm management in maize: relevance, status and prospects in Africa and Asia. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:3897-3916. [PMID: 35320376 PMCID: PMC9729323 DOI: 10.1007/s00122-022-04073-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 03/01/2022] [Indexed: 05/16/2023]
Abstract
Sustainable control of fall armyworm (FAW) requires implementation of effective integrated pest management (IPM) strategies, with host plant resistance as a key component. Significant opportunities exist for developing and deploying elite maize cultivars with native genetic resistance and/or transgenic resistance for FAW control in both Africa and Asia. The fall armyworm [Spodoptera frugiperda (J.E. Smith); FAW] has emerged as a serious pest since 2016 in Africa, and since 2018 in Asia, affecting the food security and livelihoods of millions of smallholder farmers, especially those growing maize. Sustainable control of FAW requires implementation of integrated pest management strategies, in which host plant resistance is one of the key components. Significant strides have been made in breeding elite maize lines and hybrids with native genetic resistance to FAW in Africa, based on the strong foundation of insect-resistant tropical germplasm developed at the International Maize and Wheat Improvement Center, Mexico. These efforts are further intensified to develop and deploy elite maize cultivars with native FAW tolerance/resistance and farmer-preferred traits suitable for diverse agro-ecologies in Africa and Asia. Independently, genetically modified Bt maize with resistance to FAW is already commercialized in South Africa, and in a few countries in Asia (Philippines and Vietnam), while efforts are being made to commercialize Bt maize events in additional countries in both Africa and Asia. In countries where Bt maize is commercialized, it is important to implement a robust insect resistance management strategy. Combinations of native genetic resistance and Bt maize also need to be explored as a path to more effective and sustainable host plant resistance options. We also highlight the critical gaps and priorities for host plant resistance research and development in maize, particularly in the context of sustainable FAW management in Africa and Asia.
Collapse
Affiliation(s)
- Boddupalli M Prasanna
- International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, P.O. Box 1041, GigiriNairobi, 00621, Kenya.
| | - Anani Bruce
- International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, P.O. Box 1041, GigiriNairobi, 00621, Kenya
| | - Yoseph Beyene
- International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, P.O. Box 1041, GigiriNairobi, 00621, Kenya
| | - Dan Makumbi
- International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, P.O. Box 1041, GigiriNairobi, 00621, Kenya
| | - Manje Gowda
- International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, P.O. Box 1041, GigiriNairobi, 00621, Kenya
| | | | | | - Graham P Head
- Regulatory Science, Bayer Crop Science US, Chesterfield, MO, USA
| | | |
Collapse
|
5
|
de Oliveira JL, Fraceto LF, Bravo A, Polanczyk RA. Encapsulation Strategies for Bacillus thuringiensis: From Now to the Future. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:4564-4577. [PMID: 33848162 DOI: 10.1021/acs.jafc.0c07118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bacillus thuringiensis (Bt) has been recognized for its high potential in the control of various agricultural pests. Developments in micro/nanotechnology have opened new perspectives for the production of more efficient formulations that can overcome some obstacles associated with its use in the field, such as formulation instability and loss of activity as a result of the degradation of pesticidal protein by its exposure to ultraviolet radiation, among other problems. This review describes current studies and recent discoveries related to Bt and processes for the encapsulation of Bt derivatives, such as Cry pesticidal proteins. Different techniques are described, such as extrusion, emulsion, spray drying, spray cooling, fluidized bed, lyophilization, coacervation, and electrospraying to obtain micro- and nanoparticulate systems. It is noteworthy that products based on microorganisms present less risk to the environment and non-target organisms. However, systematic risk assessment studies of these new Bt biopesticides are necessary, considering issues, such as interactions with other organisms, the formation of toxic secondary metabolites, or the interspecific transfer of genetic material. Given the great potential of these new formulations, a critical assessment is provided for their future use, considering the technological challenges that must be overcome to achieve their large-scale production for efficient agricultural use.
Collapse
Affiliation(s)
- Jhones L de Oliveira
- Department of Agricultural Production Sciences, Faculty of Agronomy and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo 14884-900, Brazil
| | - Leonardo Fernandes Fraceto
- Institute of Science and Technology, São Paulo State University (UNESP), Avenida Três de Março 511, Alto da Boa Vista, Sorocaba, São Paulo 18087-180, Brazil
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 201, Colonia Chamilpa, Cuernavaca, Morelos 62210, Mexico
| | - Ricardo Antonio Polanczyk
- Department of Agricultural Production Sciences, Faculty of Agronomy and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo 14884-900, Brazil
| |
Collapse
|
6
|
Insecticidal Activity of Bacillus thuringiensis Proteins Against Coleopteran Pests. Toxins (Basel) 2020; 12:toxins12070430. [PMID: 32610662 PMCID: PMC7404982 DOI: 10.3390/toxins12070430] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/25/2020] [Accepted: 06/25/2020] [Indexed: 12/17/2022] Open
Abstract
Bacillus thuringiensis is the most successful microbial insecticide agent and its proteins have been studied for many years due to its toxicity against insects mainly belonging to the orders Lepidoptera, Diptera and Coleoptera, which are pests of agro-forestry and medical-veterinary interest. However, studies on the interactions between this bacterium and the insect species classified in the order Coleoptera are more limited when compared to other insect orders. To date, 45 Cry proteins, 2 Cyt proteins, 11 Vip proteins, and 2 Sip proteins have been reported with activity against coleopteran species. A number of these proteins have been successfully used in some insecticidal formulations and in the construction of transgenic crops to provide protection against main beetle pests. In this review, we provide an update on the activity of Bt toxins against coleopteran insects, as well as specific information about the structure and mode of action of coleopteran Bt proteins.
Collapse
|
7
|
Natural insecticidal proteins, the promising bio-control compounds for future crop protection. THE NUCLEUS 2020. [DOI: 10.1007/s13237-020-00316-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
8
|
Lv J, Zhang X, Gao T, Cui T, Peng Q, Zhang J, Song F. Effect of the spoIIID mutation on mother cell lysis in Bacillus thuringiensis. Appl Microbiol Biotechnol 2019; 103:4103-4112. [PMID: 30953122 DOI: 10.1007/s00253-019-09722-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/19/2019] [Accepted: 02/23/2019] [Indexed: 11/28/2022]
Abstract
SpoIIID is a small, sequence-specific DNA-binding protein which can direct many genes' transcription and has an effect on spore formation in Bacillus subtilis. We investigated the role of SpoIIID in mother cell lysis in Bacillus thuringiensis. A β-galactosidase assay based on the promoter fusions with lacZ indicated that the sigK gene was positively regulated by SpoIIID and σK negatively regulated the expression of sigE. The spoIIID mutant strain exhibited no mother cell lysis in Schaeffer's sporulation medium (SSM) but did in ½ Luria-Bertani (LB) medium. cwlC is an essential hydrolase gene for mother cell lysis. Moreover, the expression of a PcwlC-lacZ fusion in spoIIID mutant was proved to be higher in ½ LB medium than in SSM. HD (ΔspoIIID)(ΔcwlC) mutant was obtained by knocking out the cwlC gene in HD(ΔspoIIID) and displayed no mother cell lysis in both SSM and ½ LB mediums. The deletion of spoIIID decreased the crystal protein production in HD73. The expression of Porf1cry8E and P5014 promoter fusions with lacZ gene in the acrystalliferous HD-(ΔspoIIID) mutant showed similar activity to that in the acrystalliferous HD73- strain before T7 and slightly higher than that in the acrystalliferous HD73- after T7. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that Cry1Ac production in HD-(ΔspoIIID) directed by the Porf1cry8E and P5014 promoters was at a similar level as that in HD73 wild strain. Altogether, these results suggested that the spoIIID mutant with Porf1cry8E or P5014 promoters could be an alternative delivery system for cry gene expression with no mature spore formation and medium-dependent mother cell lysis.
Collapse
Affiliation(s)
- Jing Lv
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xin Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Tantan Gao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Tingting Cui
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Qi Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Fuping Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| |
Collapse
|
9
|
A strong promoter of a non-cry gene directs expression of the cry1Ac gene in Bacillus thuringiensis. Appl Microbiol Biotechnol 2018. [DOI: 10.1007/s00253-018-8836-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
10
|
He X, Sun Z, He K, Guo S. Biopolymer microencapsulations of Bacillus thuringiensis crystal preparations for increased stability and resistance to environmental stress. Appl Microbiol Biotechnol 2017; 101:2779-2789. [PMID: 28050633 DOI: 10.1007/s00253-016-8070-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/12/2016] [Accepted: 12/17/2016] [Indexed: 10/20/2022]
Abstract
Parasporal crystals synthesized by Bacillus thuringiensis (Bt) have been widely used as microbial pesticides because of their toxicity to the larval stages of specific insects. However, parasporal crystals can be damaged by environmental stresses, such as high temperature, ultraviolet radiation, and desiccation. To reduce environmental susceptibility of parasporal crystals and extend the duration of their activity, we developed a new type of protection by making microcapsules of crystals (MCs). The microcapsules were self-assembled by alternate deposition (layer by layer) of low-cost chitosan and sodium alginate (or sodium carboxymethyl cellulose) on the crystal surface. Crystal toxins (Cry1Ac) were released from microcapsules at pH values above 9.0. Bioassay results demonstrated that microencapsulated preparations had larvicidal toxicity equivalent to the non-encapsulated form. Microencapsuled crystals were protected from environmental stresses such as high temperature and desiccation. The results indicate that microcapsule protection can enhance the efficacy of Bt in pest control, especially to Lepidoptera larvae that have a alkaline midgut.
Collapse
Affiliation(s)
- Xiaolin He
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhongqin Sun
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Kanglai He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
| | - Shuyuan Guo
- School of Life Science, Beijing Institute of Technology, Beijing, China.
| |
Collapse
|
11
|
Han G, Li C, Liu Q, Xu J. Synergistic Effect of Combining Plutella xylostella Granulovirus and Bacillus thuringiensis at Sublethal Dosages on Controlling of Diamondback Moth (Lepidoptera: Plutellidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2015; 108:2184-2191. [PMID: 26453707 DOI: 10.1093/jee/tov182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/15/2015] [Indexed: 06/05/2023]
Abstract
Plutella xylostella granulovirus (PxGV) and Bacillus thuringiensis (Bt) are both entomo-pathogens to the diamondback moth, Plutella xylostella (L.). The purpose of the present study was to measure the effect of the combination of PxGV and Bt at sublethal dosages on the development and mortality of diamondback moth in a laboratory setting. Bt and PxGV exhibited synergistic effect on diamondback moth larval mortality and effectively controlled diamondback moth populations with low dose combination treatment. The combination of three parts per million Bt and 1.3 × 10(3) occlusion bodies per milliliter of PxGV revealed a higher larval mortality compared with the treatment of Bt or PxGV alone. Combination of Bt and PxGV at sublethal concentrations also increased larval duration, reduced oviposition and decreased adult longevity remarkably, resulting in the lowest population trend index among the treatments. The results suggested that the combination of Bt and PxGV at sublethal dosages might provide a valuable way to improve the control efficacy of diamondback moth compared with treatment of Bt or PxGV alone.
Collapse
Affiliation(s)
- Guangjie Han
- Jiangsu Lixiahe Institute of Agricultural Sciences, Yangzhou 225008, P. R. China. College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China.
| | - Chuanming Li
- Jiangsu Lixiahe Institute of Agricultural Sciences, Yangzhou 225008, P. R. China. College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, P. R. China
| | - Qin Liu
- Jiangsu Lixiahe Institute of Agricultural Sciences, Yangzhou 225008, P. R. China
| | - Jian Xu
- Jiangsu Lixiahe Institute of Agricultural Sciences, Yangzhou 225008, P. R. China.
| |
Collapse
|
12
|
Crystal structure of Cry51Aa1: A potential novel insecticidal aerolysin-type β-pore-forming toxin from Bacillus thuringiensis. Biochem Biophys Res Commun 2015; 462:184-9. [DOI: 10.1016/j.bbrc.2015.04.068] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 04/12/2015] [Indexed: 11/23/2022]
|
13
|
Koch MS, Ward JM, Levine SL, Baum JA, Vicini JL, Hammond BG. The food and environmental safety of Bt crops. FRONTIERS IN PLANT SCIENCE 2015; 6:283. [PMID: 25972882 PMCID: PMC4413729 DOI: 10.3389/fpls.2015.00283] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/08/2015] [Indexed: 05/28/2023]
Abstract
Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms.
Collapse
|
14
|
Koch MS, Ward JM, Levine SL, Baum JA, Vicini JL, Hammond BG. The food and environmental safety of Bt crops. FRONTIERS IN PLANT SCIENCE 2015; 6:283. [PMID: 25972882 DOI: 10.3389/fpls.2015.0028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/08/2015] [Indexed: 05/28/2023]
Abstract
Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms.
Collapse
|
15
|
Gindin G, Mendel Z, Levitin B, Kumar P, Levi T, Shahi P, Khasdan V, Weinthal D, Kuznetsova T, Einav M, Kushmaro A, Protasov A, Zaritsky A, Ben-Dov E. The basis for rootstock resilient to Capnodis species: screening for genes encoding δ-endotoxins from Bacillus thuringiensis. PEST MANAGEMENT SCIENCE 2014; 70:1283-1290. [PMID: 24293325 DOI: 10.1002/ps.3694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 10/22/2013] [Accepted: 11/29/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Conventional methods often fail to control the flatheaded borers Capnodis spp., major pests of stone fruit trees; the larvae are protected from insecticides and predation because they feed deep in the roots. A potential solution is transgenic trees producing in their roots toxic compounds such as Cry proteins of Bacillus thuringiensis (Bt). RESULTS Toxicities against Capnodis larvae were demonstrated by exploiting a recently designed artificial larval diet and an available collection of field isolated Bt. An isolate of Bt tenebrionis (Btt) from commercial bioinsecticide (Novodor) displayed LC50 and LC95 values of 3.2 and 164 mg g(-1) , respectively, against neonates of Capnodis tenebrionis, whereas values of the most toxic field isolate K-7 were 1.9 and 25.6 mg g(-1) respectively. Weights of surviving larvae after 1 month on diets containing low concentrations of K-7 (0.1-1.0 mg g(-1) ) were lower than on Btt or untreated larvae. K-7 was also toxic against larvae of C. cariosa and C. miliaris and found to harbour genes encoding Cry9Ea-like and Cry23Aa/Cry37Aa binary toxins. CONCLUSION Larvae of Capnodis spp. are susceptible to Bt Cry toxins. Expressing cry genes active against these pests thus seems a feasible solution towards production of transgenic rootstock trees resilient to the pest.
Collapse
Affiliation(s)
- Galina Gindin
- Department of Entomology, Agricultural Research Organisation, The Volcani Centre, Bet Dagan, Israel
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Ekino K, Okumura S, Ishikawa T, Kitada S, Saitoh H, Akao T, Oka T, Nomura Y, Ohba M, Shin T, Mizuki E. Cloning and characterization of a unique cytotoxic protein parasporin-5 produced by Bacillus thuringiensis A1100 strain. Toxins (Basel) 2014; 6:1882-95. [PMID: 24945755 PMCID: PMC4073135 DOI: 10.3390/toxins6061882] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 05/29/2014] [Accepted: 06/09/2014] [Indexed: 11/16/2022] Open
Abstract
Parasporin is the cytocidal protein present in the parasporal inclusion of the non-insecticidal Bacillus thuringiensis strains, which has no hemolytic activity but has cytocidal activities, preferentially killing cancer cells. In this study, we characterized a cytocidal protein that belongs to this category, which was designated parasporin-5 (PS5). PS5 was purified from B. thuringiensis serovar tohokuensis strain A1100 based on its cytocidal activity against human leukemic T cells (MOLT-4). The 50% effective concentration (EC₅₀) of PS5 to MOLT-4 cells was approximately 0.075 μg/mL. PS5 was expressed as a 33.8-kDa inactive precursor protein and exhibited cytocidal activity only when degraded by protease at the C-terminal into smaller molecules of 29.8 kDa. Although PS5 showed no significant homology with other known parasporins, a Position Specific Iterative-Basic Local Alignment Search Tool (PSI-BLAST) search revealed that the protein showed slight homology to, not only some B. thuringiensis Cry toxins, but also to aerolysin-type β-pore-forming toxins (β-PFTs). The recombinant PS5 protein could be obtained as an active protein only when it was expressed in a precursor followed by processing with proteinase K. The cytotoxic activities of the protein against various mammalian cell lines were evaluated. PS5 showed strong cytocidal activity to seven of 18 mammalian cell lines tested, and low to no cytotoxicity to the others.
Collapse
Affiliation(s)
- Keisuke Ekino
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan.
| | - Shiro Okumura
- Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, 1465-5 Aikawa-machi, Kurume, Fukuoka 839-0861, Japan.
| | - Tomoyuki Ishikawa
- Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, 1465-5 Aikawa-machi, Kurume, Fukuoka 839-0861, Japan.
| | - Sakae Kitada
- Department of Bioscience and Bioinfomatics, Kyushu Institute of Technology, Iizuka, Fukuoka 820-8502, Japan.
| | - Hiroyuki Saitoh
- Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, 1465-5 Aikawa-machi, Kurume, Fukuoka 839-0861, Japan.
| | - Tetsuyuki Akao
- Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, 1465-5 Aikawa-machi, Kurume, Fukuoka 839-0861, Japan.
| | - Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan.
| | - Yoshiyuki Nomura
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan.
| | - Michio Ohba
- Graduate School of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
| | - Takashi Shin
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan.
| | - Eiichi Mizuki
- Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, 1465-5 Aikawa-machi, Kurume, Fukuoka 839-0861, Japan.
| |
Collapse
|
17
|
Screening of cry-type promoters with strong activity and application in Cry protein encapsulation in a sigK mutant. Appl Microbiol Biotechnol 2014; 98:7901-9. [PMID: 24928660 DOI: 10.1007/s00253-014-5874-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/15/2014] [Accepted: 05/24/2014] [Indexed: 10/25/2022]
Abstract
To optimize the expression of cry genes in a Bacillus thuringiensis sigK mutant failing in crystal releasing, the transcriptional activity of the cry promoters cry1A, cry3A, cry4A, and cry8E was compared using lacZ gene fusions. A beta-galactosidase assay indicated that the cry8E promoter showed the highest transcriptional activity. A novel Escherichia coli-B. thuringiensis shuttle vector pHT315-8E21b was constructed for cry gene expression using the cry8E promoter and the multiple cloning sites from vector pET21b, based on vector pHT315. SDS-PAGE analysis showed that the expression of the cry1Ac gene directed by the cry8E promoter was increased by approximately 2.4-fold over the expression directed by the cry3A promoter. The cry1Ba gene was expressed in the sigK mutant with the constructed vector pHT315-8E21b. Normal bipyramidal crystals encapsulated in mother cell were observed by transmission electron microscopy (TEM). The encapsulated Cry1Ba protein expressed in the sigK mutant showed activity against Ostrinia furnacalis and Plutella xylostella similar to that of the released Cry1Ba protein expressed in the acrystalliferous strain HD73 and can be protected from inactivation by UV light. All these results suggest that the cry8E promoter can be an efficient transcriptional element for cry gene expression in sigK mutants and can be utilized for the construction of a genetically engineered strain.
Collapse
|
18
|
Li F, Yan Y, Wang D, Zhang J, Guo S. Cry8Ca2-containing layer-by-layer microcapsules for the pH-controlled release of crystal protein. J Microencapsul 2014; 31:567-72. [DOI: 10.3109/02652048.2014.885609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
19
|
Ai B, Li J, Feng D, Li F, Guo S. The elimination of DNA from the Cry toxin-DNA complex is a necessary step in the mode of action of the Cry8 toxin. PLoS One 2013; 8:e81335. [PMID: 24324685 PMCID: PMC3852532 DOI: 10.1371/journal.pone.0081335] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/17/2013] [Indexed: 11/30/2022] Open
Abstract
Several crystal (Cry) proteins are known to occur as DNA-protein complexes. However, the role of the DNA associated with the activated toxin in the mechanism of action of the Cry toxin has long been ignored. Here, we focused on the DNA-activated Cry toxin complex. Both forms of the Cry8Ca2 and Cry8Ea1 toxins, i.e., with or without bound DNA, were separately obtained. Size-exclusion chromatography analysis indicated that the Cry8Ca2 toxin-DNA complex has a tight or compact structure. The Cry8Ca2 toxin-DNA complex is more likely to move toward the air/water interface and is more hydrophobic than the toxin without DNA. Competitive binding assays indicated that the Cry8Ca2 and Cry8Ea1 toxins without DNA specifically bind to the midgut of Anomala corpulenta and Holotrichia parallela larvae, respectively. In contrast, the association of DNA with each toxin might result in the nonspecific recognition of the Cry toxin and its target receptor in the insect midgut. The association of the DNA fragment with the Cry8 toxin was shown to protect the Cry protein from digestion by proteases. Based on our results, we propose an additional step in the mechanism of action of the Cry8 toxin and elucidate the function of the associated DNA as well as the importance of the removal of this DNA for the insecticidal activity of the toxin.
Collapse
Affiliation(s)
- Bingjie Ai
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Jie Li
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Dongmei Feng
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Feng Li
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Shuyuan Guo
- School of Life Science, Beijing Institute of Technology, Beijing, China
- * E-mail:
| |
Collapse
|
20
|
Structural analysis and molecular dynamics simulations of novel δ-endotoxin Cry1Id from Bacillus thuringiensis to pave the way for development of novel fusion proteins against insect pests of crops. J Mol Model 2013; 19:5301-16. [PMID: 24154610 DOI: 10.1007/s00894-013-2010-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 09/09/2013] [Indexed: 10/26/2022]
Abstract
The theoretical three-dimensional structure of a novel δ-endotoxin Cry1Id (81 kDa) belonging to Cry1I class, toxic to many of the lepidopteran pests has been investigated through comparative modeling. Molecular dynamics (MD) simulations was carried out to characterize its structural and dynamical features at 10 ns in explicit solvent using the GROMACS version 4.5.4. Finally the simulated model was validated by the SAVES, WHAT IF, MetaMQAP, ProQ, ModFOLD and MolProbity servers. Despite low sequence identity with its structural homologs, Cry1Id not only resembles the previously reported Cry structures but also shares the common five conserved blocks of amino acid residues. Although the domain II of Cry1Id superpose well with its closest structural homolog Cry8Ea1, variation of amino acids and length in the apical loop2 of domain II was observed. In this work, we have hypothesized that the variations in apical loop2 might be the sole factor for providing variable surface accessibility to Cry1Id protein that could be important in receptor recognition. MD simulation showed the proposed endotoxin retains its stable conformation in aqueous solution. The result from this study is expected to aid in the development hybrid Cry proteins and new potent fusion proteins with novel specificities against different insect pests for improved pest management of crop plants.
Collapse
|
21
|
van Frankenhuyzen K. Cross-order and cross-phylum activity of Bacillus thuringiensis pesticidal proteins. J Invertebr Pathol 2013; 114:76-85. [PMID: 23747826 DOI: 10.1016/j.jip.2013.05.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/20/2013] [Accepted: 05/21/2013] [Indexed: 10/26/2022]
Abstract
The increasing number of Bacillus thuringiensis proteins with pesticidal activities across orders and phyla raises the question how widespread cross-activities are and if they are of sufficient biological significance to have implications for ecological safety of those proteins in pest control applications. Cross-activity is reported for 27 proteins and 69 taxa and is substantiated by reasonable evidence (mortality estimates) in 19 cases involving 45 taxa. Cross-activities occur in 13 primary rank families across three classes of pesticidal proteins (Cry, Cyt and Vip), and comprise 13 proteins affecting species across two orders, five proteins affecting three orders and one protein affecting four orders, all within the class Insecta. Cross-activity was quantified (LC50 estimates) for 16 proteins and 25 taxa. Compared to toxicity ranges established for Diptera-, Coleoptera-, Lepidoptera- and Nematoda-active proteins, 13 cross-activities are in the low-toxicity range (10-1000μg/ml), 12 in the medium - (0.10-10μg/ml) and two in the high-toxicity range (0.01-0.10μg/ml). Although cross-activities need to be viewed with caution until they are confirmed through independent testing, current evidence suggests that cross-activity of B. thuringiensis pesticidal proteins needs to be taken into consideration when designing and approving their use in pest control applications.
Collapse
Affiliation(s)
- Kees van Frankenhuyzen
- Great Lakes Forestry Centre, Canadian Forest Service, Natural Resources Canada, 1219 Queen Street East, Sault Ste. Marie, Ontario P6A 2E5, Canada.
| |
Collapse
|
22
|
Affiliation(s)
| | | | - John E. Linz
- Department of Food Science and Human Nutrition,
- Department of Microbiology and Molecular Genetics,
- National Food Safety and Toxicology Center,
- Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824;
| |
Collapse
|
23
|
Yang W, He K, Zhang J, Guo S. pH-controlled Bacillus thuringiensis Cry1Ac protoxin loading and release from polyelectrolyte microcapsules. PLoS One 2012; 7:e45233. [PMID: 23024810 PMCID: PMC3443234 DOI: 10.1371/journal.pone.0045233] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 08/17/2012] [Indexed: 11/18/2022] Open
Abstract
Crystal proteins synthesized by Bacillus thuringiensis (Bt) have been used as biopesticides because of their toxicity to the insect larval hosts. To protect the proteins from environmental stress to extend their activity, we have developed a new microcapsule formulation. Poly (acrylic acid) (PAH) and poly (styrene sulfonate) (PSS) were fabricated through layer-by-layer self-assembly based on a CaCO3 core. Cry1Ac protoxins were loaded into microcapsules through layer-by-layer self-assembly at low pH, and the encapsulated product was stored in water at 4°C. Scanning electron microscopy (SEM) was used to observe the morphology of the capsules. To confirm the successful encapsulation, the loading results were observed with a confocal laser scattering microscope (CLSM), using fluorescein-labeled Cry1Ac protoxin (FITC-Cry1Ac). The protoxins were released from the capsule under the alkaline condition corresponding to the midgut of certain insects, a condition which seldom exists elsewhere in the environment. The following bioassay experiment demonstrated that the microcapsules with Cry1Ac protoxins displayed approximately equivalent insecticidal activity to the Asian corn borer compared with free Cry1Ac protoxins, and empty capsules proved to have no effect on insects. Further result also indicated that the formulation could keep stable under the condition of heat and desiccation. These results suggest that this formulation provides a promising methodology that protects protoxins from the environment and releases them specifically in the target insects’ midgut, which has shown potential as biopesticide in the field.
Collapse
Affiliation(s)
- Wenhui Yang
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Kanglai He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shuyuan Guo
- School of Life Science, Beijing Institute of Technology, Beijing, China
- * E-mail:
| |
Collapse
|
24
|
Baum JA, Sukuru UR, Penn SR, Meyer SE, Subbarao S, Shi X, Flasinski S, Heck GR, Brown RS, Clark TL. Cotton plants expressing a hemipteran-active Bacillus thuringiensis crystal protein impact the development and survival of Lygus hesperus (Hemiptera: Miridae) nymphs. JOURNAL OF ECONOMIC ENTOMOLOGY 2012; 105:616-624. [PMID: 22606834 DOI: 10.1603/ec11207] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The plant bugs Lygus hesperus Knight (Hemiptera: Miridae) and L. lineolaris (Palisot de Beauvois) have emerged as economic pests of cotton in the United States. These hemipteran species are refractory to the insect control traits found in genetically modified commercial varieties of cotton. In this article, we report the isolation and characterization of a 35 kDa crystal protein from Bacillus thuringiensis, designated TIC807, which causes reduced mass gain and mortality of L. hesperus and L. lineolaris nymphs when presented in an artificial diet feeding assay. Cotton plants expressing the TIC807 protein were observed to impact the survival and development of L. hesperus nymphs in a concentration-dependent manner. These results, demonstrating in planta activity of a Lygus insecticidal protein, represent an important milestone in the development of cotton varieties protected from Lygus feeding damage.
Collapse
Affiliation(s)
- James A Baum
- Monsanto Company, 700 Chesterfield Parkway West, Chesterfield, MO 63017, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Gao Y, Oppert B, Lord JC, Liu C, Lei Z. Bacillus thuringiensis Cry3Aa toxin increases the susceptibility of Crioceris quatuordecimpunctata to Beauveria bassiana infection. J Invertebr Pathol 2012; 109:260-3. [DOI: 10.1016/j.jip.2011.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/26/2011] [Accepted: 12/12/2011] [Indexed: 10/14/2022]
|
26
|
Sanahuja G, Banakar R, Twyman RM, Capell T, Christou P. Bacillus thuringiensis: a century of research, development and commercial applications. PLANT BIOTECHNOLOGY JOURNAL 2011; 9:283-300. [PMID: 21375687 DOI: 10.1111/j.1467-7652.2011.00595.x] [Citation(s) in RCA: 397] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Bacillus thuringiensis (Bt) is a soil bacterium that forms spores during the stationary phase of its growth cycle. The spores contain crystals, predominantly comprising one or more Cry and/or Cyt proteins (also known as δ-endotoxins) that have potent and specific insecticidal activity. Different strains of Bt produce different types of toxin, each of which affects a narrow taxonomic group of insects. Therefore, Bt toxins have been used as topical pesticides to protect crops, and more recently the proteins have been expressed in transgenic plants to confer inherent pest resistance. Bt transgenic crops have been overwhelmingly successful and beneficial, leading to higher yields and reducing the use of chemical pesticides and fossil fuels. However, their deployment has attracted some criticism particularly with regard to the potential evolution of pest-resistant insect strains. Here, we review recent progress in the development of Bt technology and the countermeasures that have been introduced to prevent the evolution of resistant insect populations.
Collapse
Affiliation(s)
- Georgina Sanahuja
- Department of Plant Production and Forestry Science, ETSEA, University of Lleida, Lleida, Spain
| | | | | | | | | |
Collapse
|
27
|
Guo S, Li J, Liu Y, Song F, Zhang J. The role of DNA binding with the Cry8Ea1 toxin of Bacillus thuringiensis. FEMS Microbiol Lett 2011; 317:203-10. [DOI: 10.1111/j.1574-6968.2011.02230.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
28
|
Malone LA, Todd JH, Burgess EPJ, Walter C, Wagner A, Barratt BIP. Developing risk hypotheses and selecting species for assessing non-target impacts of GM trees with novel traits: the case of altered-lignin pine trees. ENVIRONMENTAL BIOSAFETY RESEARCH 2010; 9:181-98. [PMID: 22293130 DOI: 10.1051/ebr/2011109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
A procedure is presented for developing environmental risk hypotheses associated with the deployment of forest trees genetically modified to have altered wood properties and for selecting non-target species to test these hypotheses. Altered-lignin Pinus radiata trees intended for use in New Zealand are used as a hypothetical case study to illustrate our approach. Firstly, environmental management goals (such as wood production, flood control or preservation of biodiversity) were identified and linked to the forest attributes they require. Necessary conditions for each attribute were listed and appropriate assessment endpoints for them developed. For example, biological control of pests may be one condition necessary for a forest to have healthy trees, and the diversity and abundance of natural enemy species in the forest could be an appropriate assessment endpoint for measuring this condition. A conceptual model describing the relationships between an altered-lignin GM pine tree and potentially affected invertebrates and micro-organisms in a plantation forest was used to develop a set of risk hypotheses describing how the GM trees might affect each assessment endpoint. Because purified lignin does not represent the properties it imparts to wood, maximum hazard dose tests with non-target organisms, as are used to inform toxin risk assessment, cannot be conducted. Alternative experiments, based on current knowledge of the responses of organisms to lignin, must be designed. A screening method was adapted and applied to a database of invertebrate species known to inhabit New Zealand pine forests to identify and prioritize non-target invertebrate species that could be used as experimental subjects for examining these hypotheses. The screening model and its application are presented, along with a set of recommendations for pre-release tests with GM pines and potentially affected invertebrates and micro-organisms.
Collapse
Affiliation(s)
- Louise A Malone
- The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Mt Albert, Auckland Mail Centre, Auckland, New Zealand.
| | | | | | | | | | | |
Collapse
|
29
|
Guo S, Ye S, Liu Y, Wei L, Xue J, Wu H, Song F, Zhang J, Wu X, Huang D, Rao Z. Crystal structure of Bacillus thuringiensis Cry8Ea1: An insecticidal toxin toxic to underground pests, the larvae of Holotrichia parallela. J Struct Biol 2009; 168:259-66. [PMID: 19591941 DOI: 10.1016/j.jsb.2009.07.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 05/21/2009] [Accepted: 07/05/2009] [Indexed: 10/20/2022]
Abstract
Crystal (Cry) proteins belong to an insect toxin family encoded and expressed by a variety of Bacillus thuringiensis isolates, and are named due to their in vivo auto-crystallization abilities. To kill the infected host insects, protease-activated Cry toxins should firstly be recognized by certain membrane receptors on the surface of insect midgut epithelial cells and consequently assemble together as lethal transmembrane pores. Here we report the 2.2-A crystal structure of Cry8Ea1 toxin, a Cry family member specifically toxic to the underground larvae of Holotrichia parallela. Superimposition of the domain I from Cry8Ea1 and other structurally characterized Cry toxins reveals an identical surface proline residue and a highly conserved kink of a helix, both of which have drawn comparatively little attention from previous researchers. Further structural analysis and functional studies suggest that both the proline and the helix kink might be essential in exposing a helix-helix hairpin, which is believed to be the very first step in the well-known "umbrella" model of the membrane penetration. In summary, we propose a plausible model of the initiation of Cry toxin domain I disassembly before membrane penetration and pore formation.
Collapse
|
30
|
Gelernter WD. Microbial control in Asia: A bellwether for the future? J Invertebr Pathol 2007; 95:161-7. [PMID: 17467731 DOI: 10.1016/j.jip.2007.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2007] [Accepted: 03/10/2007] [Indexed: 11/24/2022]
Abstract
Advances and barriers faced by microbial control efforts in Asia offer instructive insights for microbial control in general. The papers in this series, which are based on plenary lectures given at the Society for Invertebrate Pathology 2006 meeting in Wuhan, China, explore the history and current status of microbial control in China, Japan, and Southeast Asia, and in doing so, bring to light the following key assumptions that deserve further examination; (1) the adoption rate of microbial control is well documented; (2) microbial control agents can compete directly with conventional insecticides; (3) microbial control agents are relatively easy and inexpensive to produce and develop; (4) patents will promote innovation and investor interest in microbial control. Alternative viewpoints are presented that can hopefully aid in future efforts to develop more safe and effective microbial control agents.
Collapse
|